Peripheral occlusion is used clinically for a wide variety of vascular pathologies. One type of device is a vascular plug, which has been used to treat pulmonary arteriovenous malformations, anomalous venous connections, and internal iliac artery aneurysm with or without abdominal aortic aneurysm. Typical vascular occlusion devices or plugs can generally occlude blood flow through a branching vessel or other vessel.
One type of plug is in the form of an expandable mesh that can expand to fill a hole or gap in the heart or blood vessel. These plugs expand and over time blood will clot on the mesh and eventually block blood from travelling into or through the hole.
Another type of plug is in the form of a coil. The coil will wind into a predetermined shape within a blood vessel after deployment. Over time, blood will clot on and around the coil to eventually block blood flow into or through the vessel.
However, improvements can be made. For example, these typical vascular occlusion devices do not immediately occlude blood flow through the vessel. Rather, they require time for blood to clot on the device.
Another type of implantable medical device is in the form of a covered stent that can be used to treat peripheral disease. These covered stents include a support frame or stent that includes a graft material attached thereto. These stent-grafts are typically used to ensure that blood will continue to flow through a diseased vessel, with the stent expanding into contact with the vessel wall. The stent-graft includes a lumen therethrough that permits blood to flow. However, these devices will not occlude or prevent flow.
These stents or stent-grafts can include coverings that are typically applied when the support frame is in an expanded condition, and the stent-graft is then compressed for delivery. This compression is radially applied, and when released, the stent-graft will expand into engagement with the target blood vessel.
However, these typical covering materials are not resistance to relatively high strain, limited the amount that they can be stretched relative to their initial state. This covering material can be radially compressed and folded over itself, but this limits the amount that the devices can be compressed for delivery.
Thus, improvements can be made to covering materials that are applied to medical device support structures.